Yang P, Yin X, Rutishauser U
Department of Genetics, Case Western Reserve University, Cleveland, Ohio 44106.
J Cell Biol. 1992 Mar;116(6):1487-96. doi: 10.1083/jcb.116.6.1487.
We have previously proposed that polysialic acid (PSA), which is attached to NCAM on the cell surface, can serve to regulate a variety of cell-cell interactions. The present study provides evidence that hydrated PSA influences a sufficiently large volume at the cell surface to exert broad steric effects, and that the removal of PSA in fact causes a detectable change in intercellular space. Using F11 neuron/neuroblastoma hybrid cells as a model system, the measured density and size of PSA suggests that a substantial fraction of the space between two apposed cell surface membranes could be sterically influenced by the presence of PSA. Specific enzymatic removal of PSA, which is similar in magnitude to changes that occur in many tissues during normal development, caused about a 25% decrease in the distance between two apposed cells. By contrast, removal of both heparan sulfate and chondroitin sulfate from the cells had no effect on this parameter. It is proposed that such changes in membrane-membrane distance could serve to alter selectively the efficiency of encounter between complementary receptors on apposing cells, and explain at least in part the broad biological influences of PSA.
我们之前曾提出，附着于细胞表面神经细胞黏附分子（NCAM）上的多唾液酸（PSA）可用于调节多种细胞间相互作用。本研究提供了证据，表明水合PSA在细胞表面影响足够大的体积以发挥广泛的空间效应，并且去除PSA实际上会导致细胞间空间发生可检测到的变化。使用F11神经元/神经母细胞瘤杂交细胞作为模型系统，对PSA的密度和大小测量表明，两个相对的细胞表面膜之间的很大一部分空间可能会受到PSA存在的空间影响。特异性酶促去除PSA，其程度与正常发育过程中许多组织发生的变化相似，导致两个相对细胞之间的距离减少约25%。相比之下，从细胞中去除硫酸乙酰肝素和硫酸软骨素对该参数没有影响。有人提出，膜-膜距离的这种变化可能有助于选择性地改变相对细胞上互补受体之间相遇的效率，并至少部分解释PSA的广泛生物学影响。
